Cam-actuated timer switch

ABSTRACT

A cam-actuated timer switch, substantially thin in profile, utilizes two cam members rotating side-by-side and two sets of contact-carrying blades, each set being located on either side of a line through the centers of the two cam members.

United States Patent 191 Brown 1 June 4, 1974 [5 CAM-ACTUATED TIMERSWITCH 3,319,198 5/1967 Thomas 2011/27 R x 3.478,!81 11/1969 Buckerrid 6et a1 ZOO/38 B [75] Inventor! g Brown, Beech Grove 3,727,015 4/1973Voland et al. ZOO/38 R n [73]- Assignee: P. R. Mallory & Co. Inc.,

Indianapolis, Ind. Primary Examiner-James R. Scott Attorney, Agent, orFirm-Richard H. C hildress; [22] Charles W. Hoffmann; Robert'F. Meyer[21] Appl. No.: 346,313. 52 US. Cl 2110/38 B, 200/27 B. 200/30 R, v r l7 200/153 LB 1571 ABSTRACT [51] Int. Cl. H0111 43/10 1 1 I [58] Field ofSearch 200/27 R, 27 B, 30 R, 30A, A Cam-actuated timer switch,substantially thin in pro- 200/31 R, 31 A 38 R, 38 B, 38 BA, 38 C, 38file, utilizes two cam members rotating side-by-side CA, 153 L, 153 LA153 LB and two sets of contact-carrying blades, each set being I 1located on either side of a. line through the centers of [56] ReferencesCited the two 'cam members- 1 UNITED STATES PATENTS 7 2,877.31? 3/1959Euler et 11. 1. ZOO/38 C x 16 Claims, 7 Drawing Figures CAM-ACTUATEDTIMER SWITCH Generally speaking, the present invention relates to acam-acutated timer switch including two cam members rotating side byside in an enclosure and a long and short set of contact-carrying bladesresponsive to the cam members wherein the long set is located on oneside of a line through the centers of the cam members and the short setis located on the other side of that line. Another embodiment of thepresent invention relates to a cam-actuated timer switch including a cammember rotating in a substantially-thin enclosure wherein the enclosureincludes two groups of slots and a set of contact-carrying bladesresponsive to the cam member and disposed in one of the groups of slots.

The trend to make domestic and industrial appliances smaller and morecompact has created a demand for thin timer switches and controls foruse in these appliances. The present timer switch, being substantiallythin in cross-section adapts well to such limited-space applications.For example, the present timer switch may be used in a kitchen blenderto provide a preselected amount of on time. In this example, the timermay be located in a small molded-plastic base in which larger timerswitches would not fit.

One embodiment of the present invention utilizes two cam membersrotating side by side instead of in the conventional in-line arrangementfound in many timers. This side-by-side embodiment is thinner in adimension taken parallel to the cam axes than an in-lineversion-employing the same number and size of cam members.

The structure of the present invention allows a variety of combinationsof cam members and sets of contact-carrying blades. In an embodimentutilizing one cam member, a set of contact-carrying blades responsive tothe cam member may be disposed in one of two groups of slots so thatthey may be responsive to either direction of rotation of the cammember. In addition, the cam member may be flipped over 180 to presentthe same cam profiles to the set of contact-carrying blades in theiralternate location.

The versatility of the present invention is demonstrated again in theembodiment of the invention utilizing two cams rotating side by side.Each of a long and short set of contact-carrying blades is disposed inone of two groups of slots. The slots are located in the structure insuch a way that the long and short sets of contact-carrying blades maybe interchanged, whereby each set may be responsive to either of the twocam members. To achieve this versatile interchangeability of cam membersand contact-carrying blades, the two sets of slots are disposed oppositesides of a line through the centers of the two cam members.

The present invention also includes provisions for a contact-spacingmeans separating two contact-carrying blades in each set a predetermineddistance apart to achieve improved electrical switching characteristicsin the form of more accurately controlled air gaps between the contacts.

Accordingly, a feature of the present invention is to provide acam-actuated timer switch substantially thin in a directionsubstantially parallel to the axis of a timer motor output shaft.Another feature of the present invention is to provide a cam-actuatedtimer switch with a variety of available locations and combinations ofcam members and contact-carrying blades. Another feature of the presentinvention is to provide a camactuated timer'switch with two cams oneeach rotating on parallel shafts and in opposite directions. Anotherfeature of the present invention is to provide a camactuated timerswitch including an enclosure that substantially envelops the cammembers and contactcarrying blades and provides support, location andentrapment of the contact-carrying blades. Still another feature of theinvention is to provide a cam-actuated timer switch with a contactseparation means separating two contact-carrying blades a predetermineddistance apart to achieve improved electrical switching characteristics.Yet another feature of the present invention is to provide acam-actuated timer switch that is neat and compact in size. Anotherfeature of the present invention is to provide a cam-actuated timerswitch that is simple and economical to produce.

These and other features of the invention will become apparent from thefollowing description taken in conjunction with the accompanying drawingwherein:

FIG. 1 is an elevation view of an embodiment of the invention.

FIG. 2 is a front view of an embodiment of the invention, with the motorshown in FIG. I removed, utilizing a primary cam and a set ofcontact-carrying blades.

FIG. 3 is a front view of the same embodiment as shown in FIG. 2 withthe cam flipped over and the contact-carrying blades in an alternatelocation.

FIG. 4 is a front view of an embodiment of the invention, with the motorshown in FIG. I removed, utilizing two cams and two sets ofcontact-carrying blades.

FIG. 5 is a front view of the same embodiment shown in FIG. 4 with thecams flipped over and the sets of contact-carrying blades interchanged.

FIG. 6 is a rear view ofa slider engaging a set of contact-carryingblades.

FIG. 7 is a section taken along the line 7-7 of FIG. 4.

Referring now to the drawing, a synchronous gear motor 10 and asubstantially-thin timing means 20 are connected together by anattachment means 13. Synchronous gear motor 10 includes a gear housing11. Attachment means 13 comprises a plurality of hollow rivetsl6-inserted through holes in the gear housing 11 and substantially thintiming means 20 and headed over, thereby securing the two together.

' In the embodiment shown in FIGS. 2 and 3, cam means 26 includes aprimary cam member 32 comprising two cam tracks 34 and 36. Primary cammember 32 is carried on an output shaft 38 extending from motor 10.

In the embodiment shown in FIGS. 4, 5, and 7, cam means 27 includes aprimary cam member 40 comprising two cam tracks 42 and 44 and a camseparation means 46-. Cam separation means 46 comprises a gear 48sandwiched in between the two cam tracks 42 and 44. Cam means 27 furtherincludes a secondary cam member 50 comprising two cam tracks 52 and 54and a cam separation means 56. Secondary cam member 50 is carried on asecond shaft 49 which is rotatably journaled in a cup-shaped housing 58.Cam separation means 56 comprises a gear 57 sandwiched in between thetwo cam tracks 52 and-54. A coupling means 51 coupling the two cammembers together comprises gear 48 in engagement with gear 57.

In both embodiments, an enclosure 30 is of a substantiallyparallelpiped' shape and comprises cup-shaped housing 58 and asubstantially thin and flat cover 60. Enclosure 30 includes aratio ofthickness-to-perimeter distance of from 1/40 to 1/20 wherein thethickness is taken in a direction substantially parallel to thelongitudinal axis of output shaft 38, and the perimeter is measuredaround enclosure 30 in a plane substantially perpendicular to thelongitudinal axis of the output shaft 38. The cup-shaped housing 58includes a first set of slots 62 disposed in a wall 59 of the cup-shapedhousing as shown in FIG. 2. A second set of slots 64 is shown disposedin an alternate location in wall 59 in FIG. 3. Each set of slots 62 and64 contains a plurality of slots, and each set is located on oppositesides of a line A-B through the centers of primary cam member 40 andsecondary cam member. 50. Both sets of slots 62 and 64 are shown in theembodiment illustrated in FIGS. 4 and Electrical switching means 28includes a plurality of contact-carrying blades 66 and 68 which areinserted in one of the sets of slots 62 and 64 shown in the em bodimentillustrated in FIGS. 2 and 3. Cam follower tips 67 and 69 are disposedon the distal ends of blades 66 and 68 respectively. Electrical contacts63 appear on blades 66 and 68 also. Substantially-thin and flat cover 60of second enclosure 30 entraps the plurality of contact-carrying blades66 and 68 in one of the sets of slots 62 and 64.

Electrical switching means 29 includes a long set 70 v and a short set72 of contact-carrying blades, each set being inserted in one of thesets of slots 62 and 64 in the embodiment shown in FIGS. 4 and 5. Thelong set 70 is responsive to primary cam member 40, and the short set 72is responsive to secondary cam member 50. Cam follower tips 74 and 76are disposed on the distal ends of two of the long set ofcontact-carrying blades 70, and cam follower tips 78 and 80 are disposedon the distal ends of two of the short set of contact-carrying blades72. A first set of contacts 71 is carried by the long set ofcontact-carryin g blades 70, and a second set of contacts 73 is carriedby the short set of contactcarrying blades 72. Substantially thin andflat cover 60 of enclosure 30 entraps the long set and short set ofcontact-carrying blades 70 and 72 in the sets of slots 62 and 64.

In the embodiment shown in FIGS. 4 and 5, the long set ofcontact-carrying blades 70 is located on one side ofa line A-B throughthe centers of primary cam member 40 and secondary cam member 50, andthe short act of contact-carrying blades 72 is located on the other sideof line A-B.

A contact-spacing'means 82 comprises a slider 84 freely translatablealong one of a plurality of slider guides 86 which are disposed on theinside of cupshaped housing 58. Slider 84 includes lugs 88 and 90 whichengage the long set of contact-carrying blades 70. Slider 92 includeslugs 94 and 96 which engage the short set of contact-carrying blades 72.The long and short sets of contact-carrying blades 70 and 72 restrainsliders 84 and 92 each in contact with a slider guide 86.

In operation, synchronous gear motor causes output shaft 38 and primarycam member 40, carried on the output shaft, to rotate.

In the embodiment of the invention shown in FIGS. 2 and 3, cam means 26comprises a primary cam member 32. As primary cam member 32 rotates pastcam follower tips 68 and 66 respectively, contacts 63 make and breakaccording to profiles on cam tracks 34 and 36.

In the embodiment of the invention shown in FIGS. 4 and 5, the cam means27 comprises a primary cam member 40 and a secondary cam member 50. Asprimary cam member 40 rotates past cam follower tips 74 and 76, the longset of contact-carrying blades respond to the profiles of cam tracks 42and 44 causing electrical contacts 71 to open and close.

Gear 48 drives gear 57 on secondary earn member 50. This causes camtracks 52 and 54 to rotate past the cam follower tips 78 and 80. Theshort set of contactcarrying blades 72 respond to the profiles of camtracks 52 and 54 causing electrical contacts 73 to open and close.

Lugs 88 and on slider 84 engage two of the long set of contact-carryingblades 70 to partially sapce contacts 71 apart during their opening andclosing. Lugs 94 and 96 on slider 92 engage two of the short set ofcontact-carrying blades 72 to partially space contacts 73 apart duringtheir opening and closing.

What is claimed is:

l. A cam-actuated timer switch comprising:

a. a synchronous motor including an output shaft;

b. a cam means including a primary and a secondary cam member, whereinsaid primary cam member is carried on said output shaft and saidsecondary cam member is carried on a second shaft substantially parallelto said output shaft;

b. means connecting said secondary cam member to said primary cammember;

c. an electrical switching means responsive to said cam means includinga long and short set of contact-carrying blades wherein said long set ofcontact-carrying blades is located on one side of a line through thecenters of said primary and secondary cam members, and said short set ofcontactcarrying blades is located on the other side of said line;

d. an enclosure substantially enveloping said cam means and saidswitching means; and

e. an attachment means connecting said motor to said enclosure.

2. The cam-actuated timer switch according to claim 1 wherein saidprimary and secondary cam members each include a gear and two cam tracksseparated by a cam separation means.

3. The cam-actuated timer switch according to claim 2 wherein said camseparation means comprises said gear.

4. The cam-actuated timer switch according to claim 2 wherein said meansconnecting said primary cam member to said secondary cam membercomprises said gears on said primary and secondary cam members.

5. The cam-actuated timer switch according to claim 1 wherein said shortset of contact-carrying blades is responsive to said secondary cammember and said long set of contact-carrying blades is responsive tosaid primary cam member.

6. The cam-actuated timer switch according to claim 1 wherein saidenclosure comprises a cup-shaped housing and a substantially thin andflat cover.

7. The cam-actuated timer switch according to claim 6 wherein saidcup-shaped housing includes a plurality of slots disposed in a side wallthereof in which are disv posed said long and short sets ofcontact-carrying blades.

8. The cam-actuated timer switch according to claim 7 wherein saidsubstantially thin and flat cover entraps said long and short sets ofcontact-carrying blades in said slots.

9. The cam-actuated timer switch according to claim 1 wherein said longand short sets of contact-carrying blades are maintained in spacedrelation to each other by a contact spacing means. 7

10. The cam-actuated timer switch according to claim 9 wherein saidcontact spacing means includes at least one slider freely translatablealong one of a plurality of slider guides.

11. The cam-acutated timer switch according to claim 10 wherein one ofsaid long and short sets of contact-carrying blades restrain said sliderin contact with one of said slider guides.

12. The cam-actuated timer switch according to claim 1 wherein saidenclosure enveloping said cam means and said switching means issubstantially thin in a direction substantially parallel to said outputshaft.

13. The cam-actuated timer switch according to claim 1 wherein saidenclosure includes a ratio of thickness to perimeter. distance of from1/40 to l/20, said thickness taken in a direction substantially parallelto a longitudinal axis of said output shaft, and said perimeter measuredaround the outside of said enclosure in a plane substantiallyperpendicular to the longitudinal axis of said output shaft.

14. A cam-actuated timer switch comprising:

a. a synchronous motor including an output shaft;

b. a cam member, including two substantially concentric tracks, carriedon said output shaft;

c. a plurality of contact-carrying blades responsive to said cam tracks;

d. an enclosure substantially enveloping said cam member and carryingsaid output shaft and enveloping and carrying said plurality ofcontactcarrying blades and wherein said enclosure-is substantiallyparallelpiped in shape including a ratio of thickness to perimeterdistance of from l/40 to l/20, said thickness taken in a directionsubstantially parallel to a longitudinal axis of said output shaft, andsaid perimeter measures around the outside of said enclosure in a planesubstantially perpendicular to said longitudinal axis of said outputshaft;

e. an attachment means connecting said motor to said enclosure.

15. A cam-actuated timer switch comprising:'

a. a synchronous motor including an output shaft;

b. a cam means including a primary cam carried by said output shaft andhaving two cam tracks separated by a gear, a secondary cam membercarried on a second shaft disposed substantially parallel to said outputshaft and having two cam tracks separated by a gear, said gears engagingone another.

c. an electrical switching means responsive to said cam means includinga long and short set of contact-carrying blades wherein said long set ofcontact-carrying blades is located on one side of a line through thecenters of said primary and secondary cam members, and said short set ofcontactcarrying blades is located on the other side of said line;

d. an enclosure substantially enveloping said cam and electricalswitching means comprising a cupshaped housing and a substantially thinflat cover closing same, said cup-shaped housing having a plurality ofslots disposed in a side wall thereof in which are disposed said longand short contact carrying blades; and

e. an attachment means connecting saidmotor to said enclosure.

16. A cam-actuated timer switch comprising:

a. a synchronous motor including an output shaft;

b. a cam means including a primary cam carried by said output shaft andhaving two cam tracks separated by a gear, a secondary cam membercarried on a second shaft disposed substantially parallel to said outputshaft and having two cam tracks separated by a gear, said gears engagingone another.

c. an electrical switching means reponsive to said cam means including along and short set of contact-carrying blades wherein said long set ofcontact-carrying blades is located on one side of a line through thecenters of said primary and secondary cam members, and said short set ofcontactcarrying blades is located on the other side of said line, bothsaid long and short set maintained in spaced relation to each other by acontact spacing means;

d. an enclosure substantially enveloping said cam means and saidswitching means; and

e. an attachment means connecting said motor to said enclosure.

I mT ED STATES PATENT OFFICE 7 CERTIFICATE OF CORRECTION Patent No. 3,814 8 74. Dated 06/0 4/74 Inventor(s) William Brown It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Col. 2, line 66 after cam delete"members" ano.

insert-"Itieans"-'.,

Signed andsesled this 19th day of November 19%.

(SEAL) Attest McCOY M. GIBSON JR. 7 c. MARSHALL DANN v Attesting OfficerConunissioner of' Patents F QRM PO-105O (10-69) USCOMM-DC eoavm a v UTS.GOVERNMENT PRINTING OFFICE I989 O-SSi-S,

Q memo STATES PATENT OFFICE QERTIFICATE OF CORRECTION Dated Patent No 3,814 874 IHVGIHZOT S William Brown It is certified that error appears inthe above-identified patent and that said Letters Patent are herebycorrected as shown below:

Col. 2, line 66 after cam delete"members" anfi insert-"means,

Signed and sealed this 19th day of November 1974.

(SEAL) Attest McCOY M. GIBSON JR. 6. MARSHALL DANN Attesting OfficerCommissioner of' Patents USCOMM-DC 50376P59 9 ".5. GOVERNMENT PRINTINGOFFICE l9, O-aii-SM,

FORM PO-l 050 (10-65)

1. A cam-actuated timer switch comprising: a. a synchronous motorincluding an output shaft; b. a cam means including a primary and asecondary cam member, wherein said primary cam member is carried on saidoutput shaft and said secondary cam member is carried on a second shaftsubstantially parallel to said output shaft; b''. means connecting saidsecondary cam member to said primary cam member; c. an electricalswitching means responsive to said cam means including a long and shortset of contact-carrying blades wherein said long set of contact-carryingblades is located on one side of a line through the centers of saidprimary and secondary cam members, and said short set ofcontact-carrying blades is located on the other side of said line; d. anenclosure substantially enveloping said cam means and said switchingmeans; and e. an attachment means connecting said motor to saidenclosure.
 2. The cam-actuated timer switch according to claim 1 whereinsaid primary and secondary cam members each include a gear and two camtracks separated by a cam separation means.
 3. The cam-actuated timerswitch according to claim 2 wherein said cam separation means comprisessaid gear.
 4. The cam-actuated timer switch according to claim 2 whereinsaid means connecting said primary cam member to said secondary cammember comprises said gears on said primary and secondary cam members.5. The cam-actuated timer switch according to claim 1 wherein said shortset of contact-carrying blades is responsive to said secondary cammember and said long set of contact-carrying blades is responsive tosaid primary cam member.
 6. The cam-actuated timer switch according toclaim 1 wherein said enclosure comprises a cup-shaped housing and asubstantially thin and flat cover.
 7. The cam-actuated timer switchaccording to claim 6 wherein said cup-shaped housing includes aplurality of slots disposed in a side wall thereof in which are disposedsaid long and short sets of contact-carrying blades.
 8. The cam-actuatedtimer switch according to claim 7 wherein said substantially thin andflat cover entraps said long and short sets of contact-carrying bladesin said slots.
 9. The cam-actuated timer switch according to claim 1wherein said long and short sets of contact-carrying blades aremaintained in spaced relation to each other by a contact spacing means.10. The cam-actuated timer switch according to claim 9 wherein saidcontact spacing means includes at least one slider freely translatablealong one of a plurality of slider guides.
 11. The cam-acutated timerswitch according to claim 10 wherein one of said long and short sets ofcontact-carrying blades restrain said slider in contact with one of saidslider guides.
 12. The cam-actuated timer switch according to claim 1wherein said enclosure enveloping said cam means and said switchingmeans is substantially thin in a direction substantially parallel tosaid output shaft.
 13. The cam-actuated timer switch according to claim1 wherein said enclosure includes a ratio of thickness to perimeterdistance of from 1/40 to 1/20, said thickness taken in a directionsubstantially parallel to a longitudinal axis of said output shaft, andsaid perimeter measured around the outside of said enclosure in a planesubstantially perpendicular to the longitudinal axis of said outputshaft.
 14. A cam-actuated timer switch comprising: a. a synchronousmotor including an output shaft; b. a cam member, including twosubstantially concentric tracks, carried on said output shaft; c. aplurality of contact-carrying blades responsive to said cam tracks; d.an enclosure substantially enveloping said cam member and carrying saidoutput shaft and enveloping and carrying said plurality ofcontact-carrying blades and wherein said enclosure is substantiallyparallelpiped in shape including a ratio Of thickness to perimeterdistance of from 1/40 to 1/20, said thickness taken in a directionsubstantially parallel to a longitudinal axis of said output shaft, andsaid perimeter measures around the outside of said enclosure in a planesubstantially perpendicular to said longitudinal axis of said outputshaft; e. an attachment means connecting said motor to said enclosure.15. A cam-actuated timer switch comprising: a. a synchronous motorincluding an output shaft; b. a cam means including a primary camcarried by said output shaft and having two cam tracks separated by agear, a secondary cam member carried on a second shaft disposedsubstantially parallel to said output shaft and having two cam tracksseparated by a gear, said gears engaging one another. c. an electricalswitching means responsive to said cam means including a long and shortset of contact-carrying blades wherein said long set of contact-carryingblades is located on one side of a line through the centers of saidprimary and secondary cam members, and said short set ofcontact-carrying blades is located on the other side of said line; d. anenclosure substantially enveloping said cam and electrical switchingmeans comprising a cup-shaped housing and a substantially thin flatcover closing same, said cup-shaped housing having a plurality of slotsdisposed in a side wall thereof in which are disposed said long andshort contact carrying blades; and e. an attachment means connectingsaid motor to said enclosure.
 16. A cam-actuated timer switchcomprising: a. a synchronous motor including an output shaft; b. a cammeans including a primary cam carried by said output shaft and havingtwo cam tracks separated by a gear, a secondary cam member carried on asecond shaft disposed substantially parallel to said output shaft andhaving two cam tracks separated by a gear, said gears engaging oneanother. c. an electrical switching means reponsive to said cam meansincluding a long and short set of contact-carrying blades wherein saidlong set of contact-carrying blades is located on one side of a linethrough the centers of said primary and secondary cam members, and saidshort set of contact-carrying blades is located on the other side ofsaid line, both said long and short set maintained in spaced relation toeach other by a contact spacing means; d. an enclosure substantiallyenveloping said cam means and said switching means; and e. an attachmentmeans connecting said motor to said enclosure.